This invention relates to an electronic printer system, and, more particularly, to a printer system having improved multi-job stream printing and finishing capabilities.
Electronic printing systems typically employ a scanner for scanning image-bearing documents and conversion electronics for converting the image to image signals or pixels. The signals are stored and are read out successively to a printer for formation of the images on photoconductive output media such as a photoreceptor. When multiple jobs are to be sequentially printed, a process known as "job streaming" is commonly implemented. Job streaming is the ability of a printer system to complete successive printing jobs with a minimum of delay time between jobs. A control system associated with the image output terminal (IOT) of the machine identifies that multiple jobs have been scheduled, determines their characteristics and determines the necessary delay between jobs.
In other words, assuming a two-job scheduling, the controller will enable job number two to begin printing prior to completion of job number one.
It is common usage to have a quantity of jobs in the job stream which require some kind of finishing activity; e.g. collating, stitching and/or binding. Finishing activities require movement of mechanical components, e.g., movement of collating bins, stapler, heads and binding mechanisms. Jobs in the job stream typically are held, up until the finishing activity of the preceding job has been completed. These finishing delay times detract from the productivity of the printer. It would be desirable if a more efficient job overlap could be enabled to increase job streaming productivity.
In the prior art, U.S. Pat. No. 4,845,527 to Murata et al. discloses an automatic resetting mechanism which determines the operational status of a copying machine based on the elapsed time between successive copy instructions. Timers 1 and 2 are set for different durations of time at the termination of a first copy operation. If a copy instruction for a second copy operation is not issued to the system controller after timer 1 runs out, the controller automatically places the system in a predefined transient condition by setting a first group of copy conditions to a predetermined state. If a copy instruction still has not been issued after timer 2 runs out, the controller automatically resets the system back to start by setting a second group of copy conditions to a predetermined state. See col. 8, lines 35-col. 9, line 6.
U.S. Pat. No. 4,310,235 to Lorenzo et al. discloses a job stream programmer which allows an operator to pre-program a copying machine for automatically processing a plurality of the job production runs in succession. See col. 6, lines 37-57 and FIG. 6.
U.S. Pat. No. 3,989,371 to Valentine discloses a multi-mode copier/duplicator which includes a delay in mode change in response to an operator command in order to avoid any interruptions for a copying process. The delay mode is a change in logic in a cycle-out logic circuit wherein a signal is initiated by the operator to change one mode to another.
U.S. Pat. No. 4,035,072 to Deetz et al discloses a programmable controller to control and duplex mode. The programmable controller consists of a control program comprising a set of program instructions which enables the controller to generate a control signal to begin a process device in a timed manner. In operating the device in response to the instructions, the control program calculates the timing information in order to control the operating components of the machine.
U.S. Pat. No. 4,800,521 to Carter et al discloses a task control manager which controls a machine that executes a plurality of tasks. The method of control of the machine comprises the steps of: (1) involving a task of execution; (2) allocating operating system memory locations; (3) inserting in memory locations which relate to the tasks; (4) determining the processor which the task resides; (5) sending a request to the processor; and (6) initiating said task execution in response to a Directive.
The above identified references are generally illustrative of known prior art techniques for enabling multiple jobs in reprographic environment but utilizing programming logic to provide timing for the various interacting sub-system components. The prior art, however, does not disclose ways for optimizing through put efficiency for those jobs requiring finishing operations to be performed.